Catalogued in RISM as “Symphonies–A major; Manuscript copy; I-Ria Mss. Vess. 975” by Anonymus. RISM 854005521
Probable
Same melody and rhythm a whole step higher than an excerpt from Il barone di Montesecco: a transposed copy or arrangement. RISM titles the anonymous copy A major, but its encoded opening (an Andante, likely a slow introduction) has two sharps.
Attributed copies compared (1 of 1 encoded incipit match):
1.1.1 Andante · vl 1 · 9 of 9 pitches agree
({,3AB'C})/2D8F-A-/,2B4-8.-({3B'CxD})/,{3GAB}/'2C8E-G-/,2A4-8-3-{AB'xC}/Catalogue data and incipits come from RISM (Répertoire International des Sources Musicales), CC BY 4.0. Incipits are rendered with Verovio. Source and data: https://github.com/aaymeloglu/rism-attributions.